The present invention relates to mixing blades. In particular, the present invention is directed to mixing blades comprising a plastic or composite material, a blending apparatus using such a blade, and methods of mixing with such blades.
Material blenders are exemplified by such devices as disclosed in U.S. Pat. No. 2,692,127 to Conn. U.S. Pat. No. 2,692,127 discloses a blender comprising a disk adapted to rotate about an axis. The disk has circumferentially-spaced openings or radial slits extending therethrough. As shown in FIGS. 1-3, the portion of the disk on one side of each slit is pressed upwardly to form a hood 18 and an opening 20 through which material is propelled when the disk is rotated. Deflectors 22 extend outwardly from the opposite side of the hoods 18 in advance of the openings 20. The structure of the blender and the disk are incorporated herein by reference in their entirety.
U.S. Pat. No. 3,606,577 to Conn discloses a double-blade cutting and blending rotor consisting of a pair of axially-spaced, symmetrically oppositely-designed circular blades. The blades have impeller cups and vertical or inclined peripheral material-cutting teeth. The peripheral teeth may alternate in an up-and-down pattern. As a group, the teeth may be inclined relative to the plane of the disk at angles varying over a wide range. Thus, in FIG. 4, mixing teeth are disclosed which angle at an inclination to the plane of the disk approximately 45 degrees. The structure of the circular blades and the blending apparatus are incorporated herein by reference in their entirety.
U.S. Pat. No. 4,813,787 to Conn discloses a blending apparatus having a rotor provided with louvers and mixing teeth. The louvers have openings that vary in size and act to convey materials, which are being cut and blended, through the disk. Adjacent mixing teeth extend from the peripheral edges of the rotor and vary in angular extension. The structure of the rotor is incorporated herein by reference in its entirety.
Mixing blades or disks are generally made from metal. As a result of aggressive blending, the metal blades, particularly louvers, hoods, and mixing teeth, are prone to rapid wear and need to be replaced often.
The mixing blade of the present invention comprises a disk comprising a plastic or composite material. The blade has a longer working life than conventional metal blades, thereby providing a substantial savings in replacement and repair costs while also blending and mixing materials effectively. The disk has one or more openings or slots extending through the disk from a substantially flat top surface to a substantially flat bottom surface. The disk may also have one or more sets of mixing teeth located along its circumferential edge.